This invention relates to fiber optic connectors, and in particular, to a fiber optic connector having preterminated fibers and a single terminus connector.
Prior art connectors have been provided for field use to connect optical fibers such that light signals may be transmitted between mated connectors. Typically, each optical fiber was installed into termini which comprises a ferrule and pin body, with the ferrule being mounted to the forward end of the pin body. The optical fiber was inserted through the ferrule and adhesively secured therein. After insertion, the optical fiber being terminated would have to be polished at the forward face of the ferrule for mating with an optical fiber extending to the forward face of the ferrule of a mating connector. Polishing of the terminal ends of the terminating fibers was required for optically coupling the fibers together to transmit light signals therebetween without excessive losses in signal strength.
Other fiber optic connectors have been provided which contain fibers which are factory preterminated. Such connectors require that terminating fibers be mated to the rearward end of the preterminated fibers, and the terminating fibers are then mechanically secured within the connectors. However, such connectors do not provide a means of visually verifying that the terminating fibers have been successfully coupled with the respective ones of the preterminated fiber as the terminating fiber is being made up with the connector.
A single terminus fiber optic connector is provided having a preterminated fiber and a fiber guide tube for guiding a terminating fiber into the connector in alignment with the preterminated fiber. An index matching gel is disposed on the rearward end of the preterminated fiber and in the forward end of a bore of a fiber guide tube. A rearward section of the fiber guide tube has a window which extends from a periphery defined by a sidewall of the fiber guide tube, through the sidewall and into the bore of the fiber guide tube. An adhesive is applied through the window and onto the terminating fiber to secure the terminating fiber within the fiber guide tube once the terminating fiber is installed within the connector for mating with the preterminated fiber. The forward end of the fiber guide is preferably spaced apart from a rearward end of a ferrule which is mounted to the connector. The ferrule contains the preterminated fiber. The forward end of the ferrule and the preterminated fiber are factory polished prior to use in the field. The terminating fiber is mounted to the connector in the field. After field assembly, the terminating fiber extends into the rearward end of the ferrule and is optically coupled to the preterminated fiber by the index matching gel, which extends between the rearward end of the preterminated fiber and the forward end of the terminating fiber.
In another aspect of the present invention, a method is provided for optically coupling a terminating fiber with a preterminated fiber of a single terminus fiber optic connector. A fiber guide tube is provided for fitting within a rearward end of a pin body having a ferrule disposed in the forward end thereof. The preterminated fiber is factory installed into the ferrule. The preterminated fiber has an index matching gel on the rearward end face thereof, for optically coupling to the forward face of the terminating fiber. The terminating fiber has a terminal end portion which is first stripped of the outer buffer coating for a predetermined length, cleaved, and then is passed through the forward end of a bore in the fiber guide tube. The index matching gel is placed on a forward face of the terminating fiber as the terminating fiber is passed through the fiber guide tube. Upon entering the rearward end of a bore of the ferrule, at least a portion of the periphery of the forward terminal end of the terminating fiber is wiped free of any significant amounts of the index matching gel, such that air will escape from between the forward face of the terminating fiber and the rearward face of the preterminated fiber. The region between the forward and rearward faces of the respective terminating and preterminated fiber will be free of air, and filled with index matching gel to optically couple the terminating fiber to the preterminated fiber. An light signal is applied to the preterminated fiber as the terminating fiber is being connected to the preterminated fiber, to provide a positive indication which verifies when the two fibers are optically connected.